/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/

/*****************************************************************************
* auth.c - Network Authentication and Phase Control program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* Copyright (c) 1997 by Global Election Systems Inc.  All rights reserved.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <marc@mbsi.ca>
*   Ported to lwIP.
* 97-12-08 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
*   Ported from public pppd code.
*****************************************************************************/
/*
 * auth.c - PPP authentication and phase control.
 *
 * Copyright (c) 1993 The Australian National University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the Australian National University.  The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <net/lwip/opt.h>

#if PPP_SUPPORT					/* don't build if not configured for use in lwipopts.h */

#include "ppp_impl.h"
#include "pppdebug.h"

#include "fsm.h"
#include "lcp.h"
#include "pap.h"
#include "chap.h"
#include "auth.h"
#include "ipcp.h"

#if CBCP_SUPPORT
#include "cbcp.h"
#endif							/* CBCP_SUPPORT */

#include <net/lwip/ipv4/inet.h>

#include <string.h>

#if 0							/* UNUSED */
/* Bits in scan_authfile return value */
#define NONWILD_SERVER  1
#define NONWILD_CLIENT  2

#define ISWILD(word)  (word[0] == '*' && word[1] == 0)
#endif							/* UNUSED */

#if PAP_SUPPORT || CHAP_SUPPORT
/* The name by which the peer authenticated itself to us. */
static char peer_authname[MAXNAMELEN];
#endif							/* PAP_SUPPORT || CHAP_SUPPORT */

/* Records which authentication operations haven't completed yet. */
static int auth_pending[NUM_PPP];

/* Set if we have successfully called plogin() */
static int logged_in;

/* Set if we have run the /etc/ppp/auth-up script. */
static int did_authup;			/* @todo, we don't need this in lwip */

/* List of addresses which the peer may use. */
static struct wordlist *addresses[NUM_PPP];

#if 0							/* UNUSED */
/* Wordlist giving addresses which the peer may use
   without authenticating itself. */
static struct wordlist *noauth_addrs;

/* Extra options to apply, from the secrets file entry for the peer. */
static struct wordlist *extra_options;
#endif							/* UNUSED */

/* Number of network protocols which we have opened. */
static int num_np_open;

/* Number of network protocols which have come up. */
static int num_np_up;

#if PAP_SUPPORT || CHAP_SUPPORT
/* Set if we got the contents of passwd[] from the pap-secrets file. */
static int passwd_from_file;
#endif							/* PAP_SUPPORT || CHAP_SUPPORT */

#if 0							/* UNUSED */
/* Set if we require authentication only because we have a default route. */
static bool default_auth;

/* Hook to enable a plugin to control the idle time limit */
int (*idle_time_hook) __P((struct ppp_idle *)) = NULL;

/* Hook for a plugin to say whether we can possibly authenticate any peer */
int (*pap_check_hook) __P((void)) = NULL;

/* Hook for a plugin to check the PAP user and password */
int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp, struct wordlist **paddrs, struct wordlist **popts)) = NULL;

/* Hook for a plugin to know about the PAP user logout */
void (*pap_logout_hook) __P((void)) = NULL;

/* Hook for a plugin to get the PAP password for authenticating us */
int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL;

/*
 * This is used to ensure that we don't start an auth-up/down
 * script while one is already running.
 */
enum script_state {
	s_down,
	s_up
};

static enum script_state auth_state = s_down;
static enum script_state auth_script_state = s_down;
static pid_t auth_script_pid = 0;

/*
 * Option variables.
 * lwip: some of these are present in the ppp_settings structure
 */
bool uselogin = 0;				/* Use /etc/passwd for checking PAP */
bool cryptpap = 0;				/* Passwords in pap-secrets are encrypted */
bool refuse_pap = 0;			/* Don't wanna auth. ourselves with PAP */
bool refuse_chap = 0;			/* Don't wanna auth. ourselves with CHAP */
bool usehostname = 0;			/* Use hostname for our_name */
bool auth_required = 0;			/* Always require authentication from peer */
bool allow_any_ip = 0;			/* Allow peer to use any IP address */
bool explicit_remote = 0;		/* User specified explicit remote name */
char remote_name[MAXNAMELEN];	/* Peer's name for authentication */

#endif							/* UNUSED */

/* Bits in auth_pending[] */
#define PAP_WITHPEER    1
#define PAP_PEER        2
#define CHAP_WITHPEER   4
#define CHAP_PEER       8

/* @todo, move this somewhere */
/* Used for storing a sequence of words.  Usually malloced. */
struct wordlist {
	struct wordlist *next;
	char word[1];
};

extern char *crypt(const char *, const char *);

/* Prototypes for procedures local to this file. */

static void network_phase(int);
static void check_idle(void *);
static void connect_time_expired(void *);
#if 0
static int plogin(char *, char *, char **, int *);
#endif
static void plogout(void);
static int null_login(int);
static int get_pap_passwd(int, char *, char *);
static int have_pap_secret(void);
static int have_chap_secret(char *, char *, u32_t);
static int ip_addr_check(u32_t, struct wordlist *);

#if 0							/* PAP_SUPPORT || CHAP_SUPPORT */
static int scan_authfile(FILE *, char *, char *, char *, struct wordlist **, struct wordlist **, char *);
static void free_wordlist(struct wordlist *);
static void auth_script(char *);
static void auth_script_done(void *);
static void set_allowed_addrs(int unit, struct wordlist *addrs);
static int some_ip_ok(struct wordlist *);
static int setupapfile(char **);
static int privgroup(char **);
static int set_noauth_addr(char **);
static void check_access(FILE *, char *);
#endif	/* 0 */						/* PAP_SUPPORT || CHAP_SUPPORT */

#if 0							/* UNUSED */
/*
 * Authentication-related options.
 */
option_t auth_options[] = {
	{
		"require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
		"Require PAP authentication from peer", 1, &auth_required
	},
	{
		"+pap", o_bool, &lcp_wantoptions[0].neg_upap,
		"Require PAP authentication from peer", 1, &auth_required
	},
	{
		"refuse-pap", o_bool, &refuse_pap,
		"Don't agree to auth to peer with PAP", 1
	},
	{
		"-pap", o_bool, &refuse_pap,
		"Don't allow PAP authentication with peer", 1
	},
	{
		"require-chap", o_bool, &lcp_wantoptions[0].neg_chap,
		"Require CHAP authentication from peer", 1, &auth_required
	},
	{
		"+chap", o_bool, &lcp_wantoptions[0].neg_chap,
		"Require CHAP authentication from peer", 1, &auth_required
	},
	{
		"refuse-chap", o_bool, &refuse_chap,
		"Don't agree to auth to peer with CHAP", 1
	},
	{
		"-chap", o_bool, &refuse_chap,
		"Don't allow CHAP authentication with peer", 1
	},
	{
		"name", o_string, our_name,
		"Set local name for authentication",
		OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN
	},
	{
		"user", o_string, user,
		"Set name for auth with peer", OPT_STATIC, NULL, MAXNAMELEN
	},
	{
		"usehostname", o_bool, &usehostname,
		"Must use hostname for authentication", 1
	},
	{
		"remotename", o_string, remote_name,
		"Set remote name for authentication", OPT_STATIC,
		&explicit_remote, MAXNAMELEN
	},
	{
		"auth", o_bool, &auth_required,
		"Require authentication from peer", 1
	},
	{
		"noauth", o_bool, &auth_required,
		"Don't require peer to authenticate", OPT_PRIV, &allow_any_ip
	},
	{
		"login", o_bool, &uselogin,
		"Use system password database for PAP", 1
	},
	{
		"papcrypt", o_bool, &cryptpap,
		"PAP passwords are encrypted", 1
	},
	{
		"+ua", o_special, (void *)setupapfile,
		"Get PAP user and password from file"
	},
	{
		"password", o_string, passwd,
		"Password for authenticating us to the peer", OPT_STATIC,
		NULL, MAXSECRETLEN
	},
	{
		"privgroup", o_special, (void *)privgroup,
		"Allow group members to use privileged options", OPT_PRIV
	},
	{
		"allow-ip", o_special, (void *)set_noauth_addr,
		"Set IP address(es) which can be used without authentication",
		OPT_PRIV
	},
	{NULL}
};
#endif							/* UNUSED */
#if 0							/* UNUSED */
/*
 * setupapfile - specifies UPAP info for authenticating with peer.
 */
static int setupapfile(char **argv)
{
	FILE *ufile;
	int l;

	lcp_allowoptions[0].neg_upap = 1;

	/* open user info file */
	seteuid(getuid());
	ufile = fopen(*argv, "r");
	seteuid(0);
	if (ufile == NULL) {
		option_error("unable to open user login data file %s", *argv);
		return 0;
	}
	check_access(ufile, *argv);

	/* get username */
	if (fgets(user, MAXNAMELEN - 1, ufile) == NULL || fgets(passwd, MAXSECRETLEN - 1, ufile) == NULL) {
		option_error("unable to read user login data file %s", *argv);
		return 0;
	}
	fclose(ufile);

	/* get rid of newlines */
	l = strlen(user);
	if (l > 0 && user[l - 1] == '\n') {
		user[l - 1] = 0;
	}
	l = strlen(passwd);
	if (l > 0 && passwd[l - 1] == '\n') {
		passwd[l - 1] = 0;
	}

	return (1);
}
#endif							/* UNUSED */

#if 0							/* UNUSED */
/*
 * privgroup - allow members of the group to have privileged access.
 */
static int privgroup(char **argv)
{
	struct group *g;
	int i;

	g = getgrnam(*argv);
	if (g == 0) {
		option_error("group %s is unknown", *argv);
		return 0;
	}
	for (i = 0; i < ngroups; ++i) {
		if (groups[i] == g->gr_gid) {
			privileged = 1;
			break;
		}
	}
	return 1;
}
#endif

#if 0							/* UNUSED */
/*
 * set_noauth_addr - set address(es) that can be used without authentication.
 * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
 */
static int set_noauth_addr(char **argv)
{
	char *addr = *argv;
	int l = strlen(addr);
	struct wordlist *wp;

	wp = (struct wordlist *)malloc(sizeof(struct wordlist) + l + 1);
	if (wp == NULL) {
		novm("allow-ip argument");
	}
	wp->word = (char *)(wp + 1);
	wp->next = noauth_addrs;
	BCOPY(addr, wp->word, l);
	noauth_addrs = wp;
	return 1;
}
#endif							/* UNUSED */

/*
 * An Open on LCP has requested a change from Dead to Establish phase.
 * Do what's necessary to bring the physical layer up.
 */
void link_required(int unit)
{
	LWIP_UNUSED_ARG(unit);

	AUTHDEBUG(LOG_INFO, ("link_required: %d\n", unit));
}

/*
 * LCP has terminated the link; go to the Dead phase and take the
 * physical layer down.
 */
void link_terminated(int unit)
{
	AUTHDEBUG(LOG_INFO, ("link_terminated: %d\n", unit));
	if (lcp_phase[unit] == PHASE_DEAD) {
		return;
	}
	if (logged_in) {
		plogout();
	}
	lcp_phase[unit] = PHASE_DEAD;
	AUTHDEBUG(LOG_NOTICE, ("Connection terminated.\n"));
	pppLinkTerminated(unit);
}

/*
 * LCP has gone down; it will either die or try to re-establish.
 */
void link_down(int unit)
{
	int i;
	struct protent *protp;

	AUTHDEBUG(LOG_INFO, ("link_down: %d\n", unit));

	if (did_authup) {
		/* XXX Do link down processing. */
		did_authup = 0;
	}
	for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
		if (!protp->enabled_flag) {
			continue;
		}
		if (protp->protocol != PPP_LCP && protp->lowerdown != NULL) {
			(*protp->lowerdown)(unit);
		}
		if (protp->protocol < 0xC000 && protp->close != NULL) {
			(*protp->close)(unit, "LCP down");
		}
	}
	num_np_open = 0;			/* number of network protocols we have opened */
	num_np_up = 0;				/* Number of network protocols which have come up */

	if (lcp_phase[unit] != PHASE_DEAD) {
		lcp_phase[unit] = PHASE_TERMINATE;
	}
	pppLinkDown(unit);
}

/*
 * The link is established.
 * Proceed to the Dead, Authenticate or Network phase as appropriate.
 */
void link_established(int unit)
{
	int auth;
	int i;
	struct protent *protp;
	lcp_options *wo = &lcp_wantoptions[unit];
	lcp_options *go = &lcp_gotoptions[unit];
#if PAP_SUPPORT || CHAP_SUPPORT
	lcp_options *ho = &lcp_hisoptions[unit];
#endif							/* PAP_SUPPORT || CHAP_SUPPORT */

	AUTHDEBUG(LOG_INFO, ("link_established: unit %d; Lowering up all protocols...\n", unit));
	/*
	 * Tell higher-level protocols that LCP is up.
	 */
	for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
		if (protp->protocol != PPP_LCP && protp->enabled_flag && protp->lowerup != NULL) {
			(*protp->lowerup)(unit);
		}
	}
	if (ppp_settings.auth_required && !(go->neg_chap || go->neg_upap)) {
		/*
		 * We wanted the peer to authenticate itself, and it refused:
		 * treat it as though it authenticated with PAP using a username
		 * of "" and a password of "".  If that's not OK, boot it out.
		 */
		if (!wo->neg_upap || !null_login(unit)) {
			AUTHDEBUG(LOG_WARNING, ("peer refused to authenticate\n"));
			lcp_close(unit, "peer refused to authenticate");
			return;
		}
	}

	lcp_phase[unit] = PHASE_AUTHENTICATE;
	auth = 0;
#if CHAP_SUPPORT
	if (go->neg_chap) {
		ChapAuthPeer(unit, ppp_settings.our_name, go->chap_mdtype);
		auth |= CHAP_PEER;
	}
#endif							/* CHAP_SUPPORT */
#if PAP_SUPPORT && CHAP_SUPPORT
	else
#endif							/* PAP_SUPPORT && CHAP_SUPPORT */
#if PAP_SUPPORT
		if (go->neg_upap) {
			upap_authpeer(unit);
			auth |= PAP_PEER;
		}
#endif							/* PAP_SUPPORT */
#if CHAP_SUPPORT
	if (ho->neg_chap) {
		ChapAuthWithPeer(unit, ppp_settings.user, ho->chap_mdtype);
		auth |= CHAP_WITHPEER;
	}
#endif							/* CHAP_SUPPORT */
#if PAP_SUPPORT && CHAP_SUPPORT
	else
#endif							/* PAP_SUPPORT && CHAP_SUPPORT */
#if PAP_SUPPORT
		if (ho->neg_upap) {
			if (ppp_settings.passwd[0] == 0) {
				passwd_from_file = 1;
				if (!get_pap_passwd(unit, ppp_settings.user, ppp_settings.passwd)) {
					AUTHDEBUG(LOG_ERR, ("No secret found for PAP login\n"));
				}
			}
			upap_authwithpeer(unit, ppp_settings.user, ppp_settings.passwd);
			auth |= PAP_WITHPEER;
		}
#endif							/* PAP_SUPPORT */
	auth_pending[unit] = auth;

	if (!auth) {
		network_phase(unit);
	}
}

/*
 * Proceed to the network phase.
 */
static void network_phase(int unit)
{
	int i;
	struct protent *protp;
	lcp_options *go = &lcp_gotoptions[unit];

	/*
	 * If the peer had to authenticate, run the auth-up script now.
	 */
	if ((go->neg_chap || go->neg_upap) && !did_authup) {
		/* XXX Do setup for peer authentication. */
		did_authup = 1;
	}
#if CBCP_SUPPORT
	/*
	 * If we negotiated callback, do it now.
	 */
	if (go->neg_cbcp) {
		lcp_phase[unit] = PHASE_CALLBACK;
		(*cbcp_protent.open)(unit);
		return;
	}
#endif							/* CBCP_SUPPORT */

	lcp_phase[unit] = PHASE_NETWORK;
	for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
		if (protp->protocol < 0xC000 && protp->enabled_flag && protp->open != NULL) {
			(*protp->open)(unit);
			if (protp->protocol != PPP_CCP) {
				++num_np_open;
			}
		}
	}

	if (num_np_open == 0) {
		/* nothing to do */
		lcp_close(0, "No network protocols running");
	}
}

/* @todo: add void start_networks(void) here (pppd 2.3.11) */

/*
 * The peer has failed to authenticate himself using `protocol'.
 */
void auth_peer_fail(int unit, u16_t protocol)
{
	LWIP_UNUSED_ARG(protocol);

	AUTHDEBUG(LOG_INFO, ("auth_peer_fail: %d proto=%X\n", unit, protocol));
	/*
	 * Authentication failure: take the link down
	 */
	lcp_close(unit, "Authentication failed");
}

#if PAP_SUPPORT || CHAP_SUPPORT
/*
 * The peer has been successfully authenticated using `protocol'.
 */
void auth_peer_success(int unit, u16_t protocol, char *name, int namelen)
{
	int pbit;

	AUTHDEBUG(LOG_INFO, ("auth_peer_success: %d proto=%X\n", unit, protocol));
	switch (protocol) {
	case PPP_CHAP:
		pbit = CHAP_PEER;
		break;
	case PPP_PAP:
		pbit = PAP_PEER;
		break;
	default:
		AUTHDEBUG(LOG_WARNING, ("auth_peer_success: unknown protocol %x\n", protocol));
		return;
	}

	/*
	 * Save the authenticated name of the peer for later.
	 */
	if (namelen > (int)sizeof(peer_authname) - 1) {
		namelen = sizeof(peer_authname) - 1;
	}
	BCOPY(name, peer_authname, namelen);
	peer_authname[namelen] = 0;

	/*
	 * If there is no more authentication still to be done,
	 * proceed to the network (or callback) phase.
	 */
	if ((auth_pending[unit] &= ~pbit) == 0) {
		network_phase(unit);
	}
}

/*
 * We have failed to authenticate ourselves to the peer using `protocol'.
 */
void auth_withpeer_fail(int unit, u16_t protocol)
{
	int errCode = PPPERR_AUTHFAIL;

	LWIP_UNUSED_ARG(protocol);

	AUTHDEBUG(LOG_INFO, ("auth_withpeer_fail: %d proto=%X\n", unit, protocol));
	if (passwd_from_file) {
		BZERO(ppp_settings.passwd, MAXSECRETLEN);
	}

	/*
	 * We've failed to authenticate ourselves to our peer.
	 * He'll probably take the link down, and there's not much
	 * we can do except wait for that.
	 */
	pppIOCtl(unit, PPPCTLS_ERRCODE, &errCode);
	lcp_close(unit, "Failed to authenticate ourselves to peer");
}

/*
 * We have successfully authenticated ourselves with the peer using `protocol'.
 */
void auth_withpeer_success(int unit, u16_t protocol)
{
	int pbit;

	AUTHDEBUG(LOG_INFO, ("auth_withpeer_success: %d proto=%X\n", unit, protocol));
	switch (protocol) {
	case PPP_CHAP:
		pbit = CHAP_WITHPEER;
		break;
	case PPP_PAP:
		if (passwd_from_file) {
			BZERO(ppp_settings.passwd, MAXSECRETLEN);
		}
		pbit = PAP_WITHPEER;
		break;
	default:
		AUTHDEBUG(LOG_WARNING, ("auth_peer_success: unknown protocol %x\n", protocol));
		pbit = 0;
	}

	/*
	 * If there is no more authentication still being done,
	 * proceed to the network (or callback) phase.
	 */
	if ((auth_pending[unit] &= ~pbit) == 0) {
		network_phase(unit);
	}
}
#endif							/* PAP_SUPPORT || CHAP_SUPPORT */

/*
 * np_up - a network protocol has come up.
 */
void np_up(int unit, u16_t proto)
{
	LWIP_UNUSED_ARG(unit);
	LWIP_UNUSED_ARG(proto);

	AUTHDEBUG(LOG_INFO, ("np_up: %d proto=%X\n", unit, proto));
	if (num_np_up == 0) {
		AUTHDEBUG(LOG_INFO, ("np_up: maxconnect=%d idle_time_limit=%d\n", ppp_settings.maxconnect, ppp_settings.idle_time_limit));
		/*
		 * At this point we consider that the link has come up successfully.
		 */
		if (ppp_settings.idle_time_limit > 0) {
			TIMEOUT(check_idle, NULL, ppp_settings.idle_time_limit);
		}

		/*
		 * Set a timeout to close the connection once the maximum
		 * connect time has expired.
		 */
		if (ppp_settings.maxconnect > 0) {
			TIMEOUT(connect_time_expired, 0, ppp_settings.maxconnect);
		}
	}
	++num_np_up;
}

/*
 * np_down - a network protocol has gone down.
 */
void np_down(int unit, u16_t proto)
{
	LWIP_UNUSED_ARG(unit);
	LWIP_UNUSED_ARG(proto);

	AUTHDEBUG(LOG_INFO, ("np_down: %d proto=%X\n", unit, proto));
	if (--num_np_up == 0 && ppp_settings.idle_time_limit > 0) {
		UNTIMEOUT(check_idle, NULL);
	}
}

/*
 * np_finished - a network protocol has finished using the link.
 */
void np_finished(int unit, u16_t proto)
{
	LWIP_UNUSED_ARG(unit);
	LWIP_UNUSED_ARG(proto);

	AUTHDEBUG(LOG_INFO, ("np_finished: %d proto=%X\n", unit, proto));
	if (--num_np_open <= 0) {
		/* no further use for the link: shut up shop. */
		lcp_close(0, "No network protocols running");
	}
}

/*
 * check_idle - check whether the link has been idle for long
 * enough that we can shut it down.
 */
static void check_idle(void *arg)
{
	struct ppp_idle idle;
	u_short itime;

	LWIP_UNUSED_ARG(arg);
	if (!get_idle_time(0, &idle)) {
		return;
	}
	itime = LWIP_MIN(idle.xmit_idle, idle.recv_idle);
	if (itime >= ppp_settings.idle_time_limit) {
		/* link is idle: shut it down. */
		AUTHDEBUG(LOG_INFO, ("Terminating connection due to lack of activity.\n"));
		lcp_close(0, "Link inactive");
	} else {
		TIMEOUT(check_idle, NULL, ppp_settings.idle_time_limit - itime);
	}
}

/*
 * connect_time_expired - log a message and close the connection.
 */
static void connect_time_expired(void *arg)
{
	LWIP_UNUSED_ARG(arg);

	AUTHDEBUG(LOG_INFO, ("Connect time expired\n"));
	lcp_close(0, "Connect time expired");	/* Close connection */
}

#if 0							/* UNUSED */
/*
 * auth_check_options - called to check authentication options.
 */
void auth_check_options(void)
{
	lcp_options *wo = &lcp_wantoptions[0];
	int can_auth;
	ipcp_options *ipwo = &ipcp_wantoptions[0];
	u32_t remote;

	/* Default our_name to hostname, and user to our_name */
	if (ppp_settings.our_name[0] == 0 || ppp_settings.usehostname) {
		strcpy(ppp_settings.our_name, ppp_settings.hostname);
	}

	if (ppp_settings.user[0] == 0) {
		strcpy(ppp_settings.user, ppp_settings.our_name);
	}

	/* If authentication is required, ask peer for CHAP or PAP. */
	if (ppp_settings.auth_required && !wo->neg_chap && !wo->neg_upap) {
		wo->neg_chap = 1;
		wo->neg_upap = 1;
	}

	/*
	 * Check whether we have appropriate secrets to use
	 * to authenticate the peer.
	 */
	can_auth = wo->neg_upap && have_pap_secret();
	if (!can_auth && wo->neg_chap) {
		remote = ipwo->accept_remote ? 0 : ipwo->hisaddr;
		can_auth = have_chap_secret(ppp_settings.remote_name, ppp_settings.our_name, remote);
	}

	if (ppp_settings.auth_required && !can_auth) {
		ppp_panic("No auth secret");
	}
}
#endif							/* UNUSED */

/*
 * auth_reset - called when LCP is starting negotiations to recheck
 * authentication options, i.e. whether we have appropriate secrets
 * to use for authenticating ourselves and/or the peer.
 */
void auth_reset(int unit)
{
	lcp_options *go = &lcp_gotoptions[unit];
	lcp_options *ao = &lcp_allowoptions[0];
	ipcp_options *ipwo = &ipcp_wantoptions[0];
	u32_t remote;

	AUTHDEBUG(LOG_INFO, ("auth_reset: %d\n", unit));
	ao->neg_upap = !ppp_settings.refuse_pap && (ppp_settings.passwd[0] != 0 || get_pap_passwd(unit, NULL, NULL));
	ao->neg_chap = !ppp_settings.refuse_chap && ppp_settings.passwd[0] != 0 /*have_chap_secret(ppp_settings.user, ppp_settings.remote_name, (u32_t)0) */ ;

	if (go->neg_upap && !have_pap_secret()) {
		go->neg_upap = 0;
	}
	if (go->neg_chap) {
		remote = ipwo->accept_remote ? 0 : ipwo->hisaddr;
		if (!have_chap_secret(ppp_settings.remote_name, ppp_settings.our_name, remote)) {
			go->neg_chap = 0;
		}
	}
}

#if PAP_SUPPORT
/*
 * check_passwd - Check the user name and passwd against the PAP secrets
 * file.  If requested, also check against the system password database,
 * and login the user if OK.
 *
 * returns:
 *  UPAP_AUTHNAK: Authentication failed.
 *  UPAP_AUTHACK: Authentication succeeded.
 * In either case, msg points to an appropriate message.
 */
u_char check_passwd(int unit, char *auser, int userlen, char *apasswd, int passwdlen, char **msg, int *msglen)
{
#if 1							/* XXX Assume all entries OK. */
	LWIP_UNUSED_ARG(unit);
	LWIP_UNUSED_ARG(auser);
	LWIP_UNUSED_ARG(userlen);
	LWIP_UNUSED_ARG(apasswd);
	LWIP_UNUSED_ARG(passwdlen);
	LWIP_UNUSED_ARG(msglen);
	*msg = (char *)0;
	return UPAP_AUTHACK;		/* XXX Assume all entries OK. */
#else
	u_char ret = 0;
	struct wordlist *addrs = NULL;
	char passwd[256], user[256];
	char secret[MAXWORDLEN];
	static u_short attempts = 0;

	/*
	 * Make copies of apasswd and auser, then null-terminate them.
	 */
	BCOPY(apasswd, passwd, passwdlen);
	passwd[passwdlen] = '\0';
	BCOPY(auser, user, userlen);
	user[userlen] = '\0';
	*msg = (char *)0;

	/* XXX Validate user name and password. */
	ret = UPAP_AUTHACK;			/* XXX Assume all entries OK. */

	if (ret == UPAP_AUTHNAK) {
		if (*msg == (char *)0) {
			*msg = "Login incorrect";
		}
		*msglen = strlen(*msg);
		/*
		 * Frustrate passwd stealer programs.
		 * Allow 10 tries, but start backing off after 3 (stolen from login).
		 * On 10'th, drop the connection.
		 */
		if (attempts++ >= 10) {
			AUTHDEBUG(LOG_WARNING, ("%d LOGIN FAILURES BY %s\n", attempts, user));
			/*ppp_panic("Excess Bad Logins"); */
		}
		if (attempts > 3) {
			/* @todo: this was sleep(), i.e. seconds, not milliseconds
			 * I don't think we really need this in lwIP - we would block tcpip_thread!
			 */
			/*sys_msleep((attempts - 3) * 5); */
		}
		if (addrs != NULL) {
			free_wordlist(addrs);
		}
	} else {
		attempts = 0;			/* Reset count */
		if (*msg == (char *)0) {
			*msg = "Login ok";
		}
		*msglen = strlen(*msg);
		set_allowed_addrs(unit, addrs);
	}

	BZERO(passwd, sizeof(passwd));
	BZERO(secret, sizeof(secret));

	return ret;
#endif
}
#endif							/* PAP_SUPPORT */

#if 0							/* UNUSED */
/*
 * This function is needed for PAM.
 */

#ifdef USE_PAM

/* lwip does not support PAM*/

#endif							/* USE_PAM */

#endif							/* UNUSED */

#if 0							/* UNUSED */
/*
 * plogin - Check the user name and password against the system
 * password database, and login the user if OK.
 *
 * returns:
 *  UPAP_AUTHNAK: Login failed.
 *  UPAP_AUTHACK: Login succeeded.
 * In either case, msg points to an appropriate message.
 */
static int plogin(char *user, char *passwd, char **msg, int *msglen)
{

	LWIP_UNUSED_ARG(user);
	LWIP_UNUSED_ARG(passwd);
	LWIP_UNUSED_ARG(msg);
	LWIP_UNUSED_ARG(msglen);

	/* The new lines are here align the file when
	 * compared against the pppd 2.3.11 code */

	/* XXX Fail until we decide that we want to support logins. */
	return (UPAP_AUTHNAK);
}
#endif

/*
 * plogout - Logout the user.
 */
static void plogout(void)
{
	logged_in = 0;
}

/*
 * null_login - Check if a username of "" and a password of "" are
 * acceptable, and iff so, set the list of acceptable IP addresses
 * and return 1.
 */
static int null_login(int unit)
{
	LWIP_UNUSED_ARG(unit);
	/* XXX Fail until we decide that we want to support logins. */
	return 0;
}

/*
 * get_pap_passwd - get a password for authenticating ourselves with
 * our peer using PAP.  Returns 1 on success, 0 if no suitable password
 * could be found.
 */
static int get_pap_passwd(int unit, char *user, char *passwd)
{
	LWIP_UNUSED_ARG(unit);
	/* normally we would reject PAP if no password is provided,
	   but this causes problems with some providers (like CHT in Taiwan)
	   who incorrectly request PAP and expect a bogus/empty password, so
	   always provide a default user/passwd of "none"/"none"

	   @todo: This should be configured by the user, instead of being hardcoded here!
	 */
	if (user) {
		strcpy(user, "none");
	}
	if (passwd) {
		strcpy(passwd, "none");
	}
	return 1;
}

/*
 * have_pap_secret - check whether we have a PAP file with any
 * secrets that we could possibly use for authenticating the peer.
 */
static int have_pap_secret(void)
{
	/* XXX Fail until we set up our passwords. */
	return 0;
}

/*
 * have_chap_secret - check whether we have a CHAP file with a
 * secret that we could possibly use for authenticating `client'
 * on `server'.  Either can be the null string, meaning we don't
 * know the identity yet.
 */
static int have_chap_secret(char *client, char *server, u32_t remote)
{
	LWIP_UNUSED_ARG(client);
	LWIP_UNUSED_ARG(server);
	LWIP_UNUSED_ARG(remote);

	/* XXX Fail until we set up our passwords. */
	return 0;
}

#if CHAP_SUPPORT

/*
 * get_secret - open the CHAP secret file and return the secret
 * for authenticating the given client on the given server.
 * (We could be either client or server).
 */
int get_secret(int unit, char *client, char *server, char *secret, int *secret_len, int save_addrs)
{
#if 1
	int len;
	struct wordlist *addrs;

	LWIP_UNUSED_ARG(unit);
	LWIP_UNUSED_ARG(server);
	LWIP_UNUSED_ARG(save_addrs);

	addrs = NULL;

	if (!client || !client[0] || strcmp(client, ppp_settings.user)) {
		return 0;
	}

	len = (int)strlen(ppp_settings.passwd);
	if (len > MAXSECRETLEN) {
		AUTHDEBUG(LOG_ERR, ("Secret for %s on %s is too long\n", client, server));
		len = MAXSECRETLEN;
	}

	BCOPY(ppp_settings.passwd, secret, len);
	*secret_len = len;

	return 1;
#else
	int ret = 0, len;
	struct wordlist *addrs;
	char secbuf[MAXWORDLEN];

	addrs = NULL;
	secbuf[0] = 0;

	/* XXX Find secret. */
	if (ret < 0) {
		return 0;
	}

	if (save_addrs) {
		set_allowed_addrs(unit, addrs);
	}

	len = strlen(secbuf);
	if (len > MAXSECRETLEN) {
		AUTHDEBUG(LOG_ERR, ("Secret for %s on %s is too long\n", client, server));
		len = MAXSECRETLEN;
	}

	BCOPY(secbuf, secret, len);
	BZERO(secbuf, sizeof(secbuf));
	*secret_len = len;

	return 1;
#endif
}
#endif							/* CHAP_SUPPORT */

#if 0							/* PAP_SUPPORT || CHAP_SUPPORT */
/*
 * set_allowed_addrs() - set the list of allowed addresses.
 */
static void set_allowed_addrs(int unit, struct wordlist *addrs)
{
	if (addresses[unit] != NULL) {
		free_wordlist(addresses[unit]);
	}
	addresses[unit] = addrs;

#if 0
	/*
	 * If there's only one authorized address we might as well
	 * ask our peer for that one right away
	 */
	if (addrs != NULL && addrs->next == NULL) {
		char *p = addrs->word;
		struct ipcp_options *wo = &ipcp_wantoptions[unit];
		u32_t a;
		struct hostent *hp;

		if (wo->hisaddr == 0 && *p != '!' && *p != '-' && strchr(p, '/') == NULL) {
			hp = gethostbyname(p);
			if (hp != NULL && hp->h_addrtype == AF_INET) {
				a = *(u32_t *)hp->h_addr;
			} else {
				a = inet_addr(p);
			}
			if (a != (u32_t)-1) {
				wo->hisaddr = a;
			}
		}
	}
#endif
}
#endif	/* 0 */						/* PAP_SUPPORT || CHAP_SUPPORT */

/*
 * auth_ip_addr - check whether the peer is authorized to use
 * a given IP address.  Returns 1 if authorized, 0 otherwise.
 */
int auth_ip_addr(int unit, u32_t addr)
{
	return ip_addr_check(addr, addresses[unit]);
}

static int /* @todo: integrate this funtion into auth_ip_addr() */ ip_addr_check(u32_t addr, struct wordlist *addrs)
{
	/* don't allow loopback or multicast address */
	if (bad_ip_adrs(addr)) {
		return 0;
	}

	if (addrs == NULL) {
		return !ppp_settings.auth_required;	/* no addresses authorized */
	}

	/* XXX All other addresses allowed. */
	return 1;
}

/*
 * bad_ip_adrs - return 1 if the IP address is one we don't want
 * to use, such as an address in the loopback net or a multicast address.
 * addr is in network byte order.
 */
int bad_ip_adrs(u32_t addr)
{
	addr = ntohl(addr);
	return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || IN_MULTICAST(addr) || IN_BADCLASS(addr);
}

#if 0 /* UNUSED */				/* PAP_SUPPORT || CHAP_SUPPORT */
/*
 * some_ip_ok - check a wordlist to see if it authorizes any
 * IP address(es).
 */
static int some_ip_ok(struct wordlist *addrs)
{
	for (; addrs != 0; addrs = addrs->next) {
		if (addrs->word[0] == '-') {
			break;
		}
		if (addrs->word[0] != '!') {
			return 1;			/* some IP address is allowed */
		}
	}
	return 0;
}

/*
 * check_access - complain if a secret file has too-liberal permissions.
 */
static void check_access(FILE *f, char *filename)
{
	struct stat sbuf;

	if (fstat(fileno(f), &sbuf) < 0) {
		warn("cannot stat secret file %s: %m", filename);
	} else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
		warn("Warning - secret file %s has world and/or group access", filename);
	}
}

/*
 * scan_authfile - Scan an authorization file for a secret suitable
 * for authenticating `client' on `server'.  The return value is -1
 * if no secret is found, otherwise >= 0.  The return value has
 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
 * NONWILD_SERVER set if the secret didn't have "*" for the server.
 * Any following words on the line up to a "--" (i.e. address authorization
 * info) are placed in a wordlist and returned in *addrs.  Any
 * following words (extra options) are placed in a wordlist and
 * returned in *opts.
 * We assume secret is NULL or points to MAXWORDLEN bytes of space.
 */
static int scan_authfile(FILE *f, char *client, char *server, char *secret, struct wordlist **addrs, struct wordlist **opts, char *filename)
{
	/* We do not (currently) need this in lwip  */
	return 0;					/* dummy */
}

/*
 * free_wordlist - release memory allocated for a wordlist.
 */
static void free_wordlist(struct wordlist *wp)
{
	struct wordlist *next;

	while (wp != NULL) {
		next = wp->next;
		free(wp);
		wp = next;
	}
}

/*
 * auth_script_done - called when the auth-up or auth-down script
 * has finished.
 */
static void auth_script_done(void *arg)
{
	auth_script_pid = 0;
	switch (auth_script_state) {
	case s_up:
		if (auth_state == s_down) {
			auth_script_state = s_down;
			auth_script(_PATH_AUTHDOWN);
		}
		break;
	case s_down:
		if (auth_state == s_up) {
			auth_script_state = s_up;
			auth_script(_PATH_AUTHUP);
		}
		break;
	}
}

/*
 * auth_script - execute a script with arguments
 * interface-name peer-name real-user tty speed
 */
static void auth_script(char *script)
{
	char strspeed[32];
	struct passwd *pw;
	char struid[32];
	char *user_name;
	char *argv[8];

	if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL) {
		user_name = pw->pw_name;
	} else {
		slprintf(struid, sizeof(struid), "%d", getuid());
		user_name = struid;
	}
	slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);

	argv[0] = script;
	argv[1] = ifname;
	argv[2] = peer_authname;
	argv[3] = user_name;
	argv[4] = devnam;
	argv[5] = strspeed;
	argv[6] = NULL;

	auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL);
}
#endif	/* 0 */						/* PAP_SUPPORT || CHAP_SUPPORT */
#endif							/* PPP_SUPPORT */
